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Get ssh server fingerprints
Get your server's fingerprints to give to users to verify when they ssh in. Publickey locations may vary by distro. Fingerprints should be provided out-of-band.

List your largest installed packages.
Calculates the size on disk for each package installed on the filesystem (or removed but not purged). This is missing the $ | sort -rn which would put the biggest packges on top. That was purposely left out as the command is slightly on the slow side Also you may need to run this as root as some files can only be checked by du if you can read them ;)

Alias TAIL for automatic smart output
Run the alias command, then issue $ps aux | tail and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand. $ ${LINES:-`tput lines 2>/dev/null||echo -n 12`} Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80. The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt. Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html ) 275MB/748MB [7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~ $ In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.

Count lines in a file with grep
Returns the number of lines in a file, emulates "wc -l" behavior with grep.

Find the package that installed a command

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Binary digits Matrix effect
Prints 0's and 1's in The Matrix style. You can easily modify to print 0-9 digits using $RANDOM %10 insted of %2.

Pretty Print a simple csv in the command line
Splits the input based on commas and prints it in a nice column format. This would not work for CSV rows that have "," between quotes or with newline characters. Use only simple simple csv files.

Delete a file/directory walking subdirectories (bash4 or zsh)

extract email adresses from some file (or any other pattern)
This will catch most separators in the section of the email: dot . dash - underscore _ plus + (added for gmail) ... and the basic dash '-' of host names.


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